package controller;

import java.io.IOException;
import java.io.PrintWriter;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.sql.SQLException;
import java.util.LinkedList;

import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import org.json.simple.JSONObject;
import org.json.simple.parser.JSONParser;

import model.EventModelDS;
import model.ModelInterface;
import model.User;
import model.UserModelDS;

/**
 * Servlet implementation class UserControl
 */
@WebServlet("/UserController")
public class UserController extends HttpServlet {

    private static final long serialVersionUID = 1L;
    static ModelInterface<User> model = new UserModelDS();
    private UserModelDS modelDs = (UserModelDS) model;


    public UserController() {
        super();
    }


    private void sendError(String error,HttpServletResponse response) throws IOException{
      PrintWriter out = response.getWriter();
          out.println(error);
    }


     public static String toSHA1(byte[] convertme) {
         MessageDigest md = null;
         try {
             md = MessageDigest.getInstance("SHA-1");
         }
         catch(NoSuchAlgorithmException e) {
             e.printStackTrace();
         }
         return new String(md.digest(convertme));
     }



    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
            doPost(request, response);
    }


    @SuppressWarnings("unchecked")
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {


        String action = request.getParameter("action");

        try {
            if (action != null)
            {
                if (action.equalsIgnoreCase("insert"))
                {
                    String  user     = request.getParameter("email");
                    String  password = request.getParameter("password");
//                  Integer priority = null;
//                  if (request.getParameter("priority") != null) {
//                      priority = Integer.parseInt(request.getParameter("priority"));
//                  }
                    User bean = new User();
                    bean.setUser(user);
                    bean.setPassword(password);
//                  if (priority != null)   bean.setPriority(priority);
                    UserModelDS modelDs = (UserModelDS) model;
                    if(modelDs.findByName(user) != null )
                    {
                        sendError("Questo account è già esistente", response);
                        return;
                    }
                    if(model.insert(bean) == false)
                    {
                        sendError("Errore di Connessione", response);
                        return;
                    }
                }

                else if(action.equalsIgnoreCase("update"))
                {
                    String newPassword = request.getParameter("newPassword");
                    JSONObject obj =  toJson(newPassword);
                    User user = new User();

                    if(obj != null){
                        user.setPassword(newPassword);
                        if(user.getId() == 3){
                            int priority = Integer.parseInt(request.getParameter("priority"));
                            user.setPriority(priority);
                        }
                    }
                    if(!model.update(user))
                            sendError("Errore di Connessione", response);
                }

                else if(action.equalsIgnoreCase("login"))
                {
                      HttpSession session = request.getSession();
                      LinkedList<Integer> eventsPreferred = new LinkedList<Integer>();
                      LinkedList<Integer> eventsLiked = new LinkedList<Integer>();

                      session.setAttribute("eventsPreferred", eventsPreferred);
                      session.setAttribute("eventsLiked",eventsLiked);

                      String email      = (String) request.getParameter("email");
                      String password   = (String) request.getParameter("password");
                      User user = modelDs.findByName(email);
                      if(user == null)
                      {
                          sendError("Utente non esiste.", response);
                          return;
                      }
                      String DbPassword = user.getPassword();
                      String hashed     = toSHA1(password.getBytes());
                      if(DbPassword != null)
                      {
                       if(DbPassword.equals(hashed))
                       {
                           if(user.getPriority() == 3)
                           {
                               RequestDispatcher dispatcher = getServletContext().getRequestDispatcher("/admin/Admin.jsp");
                               dispatcher.forward(request,response);
                           }
                          session.setAttribute("userId", user.getId());
                       }
                       else sendError("Credenziali non valide." , response);
                      }
                }
                else if(action.equalsIgnoreCase("logout"))
                {
                        HttpSession session = request.getSession();
                        int idUser = (int) session.getAttribute("userId");
                        LinkedList<Integer> liked =  (LinkedList<Integer>) session.getAttribute("eventsLiked");
                        LinkedList<Integer> preferred =  (LinkedList<Integer>) session.getAttribute("eventsPreferred");
                        EventModelDS es = new EventModelDS();
                        if(liked.size() != 0){
                            es.setLikeToEvent(idUser, liked);
                        }
                        if(preferred.size() != 0){
                            es.setEventAsPreferred(idUser, preferred);
                        }

                }
                else if(action.equalsIgnoreCase("remove")){
                    int id = request.getIntHeader("id");
                    if(!model.remove(id))
                        sendError("Errore DataBase", response);
                }
            }
        } catch (SQLException e) {
            //System.out.println("Error:" + e.getMessage());
        }

    }
    private JSONObject toJson(String convertJson){
        JSONParser parser = new JSONParser();

        try {
            Object obj = parser.parse(convertJson);
            JSONObject jsonObject = (JSONObject) obj;
            return jsonObject;
        }
        catch(Exception e){
            return null;
        }
    }
}